Gas classifier for containers

ABSTRACT

DEFECTIVE BOTTLES PREDUCED BY A DEFECTIVE MOLD IN A MULTI-ELEMENT MOLDING MACHINE ARE FIRST IDENTIFIED BY AN INSPECTOR BY INJECTING A CHARGE OF FLUID SUCH AS CARBON DIOXIDE GAS. DURING LATER TESTING IN TRANSIT, THE PRESENCE OF THE FLUID IN A BOTTLE IS SAMPLED TO TRIGGER A DEVICE FOR EJECTING THE BOTTLE FROM THE TEST LINE.

Sept. 20, 1971 w. s. POWERS 3,506,010

GAS CLASSIFIER FOR CONTAINERS Filed Feb. 16, 1970 4 Sheets-Sheet 1 FIG. I

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INVENTOR WHITNEY S. POWERS ATTORNEYS.

Sept. 20, 1971 w. s. POWERS GAS CLASSIFIER FOR CONTAINERS 4 Sheets-Sheet 2 Filed Feb. 16, 1970 a. .u a. 0 1O 7.

ATTORNEYS.

Sept. 20, 1971 3,606,010

- GAS CLASSIFIER FOR CONTAINERS Filed Feb. 16, 1970 4 Sheets-Sheet 5 p i 1 FIG. 3 F m I 1 E $7 1 E v E g 0 2 k m 6 6 g u g /3 V a E Z /2 /4 02: Z W w INVENTOR WHITNEY S. POWERS MM .M

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Sept. 20, 1971 POWERS 3,606,010

GAS CLASSIFIER ,r'on com'unnas Filed Feb. 16, 1970 4 Sheets-Sheet 4 //0 1/. LQJMIMQSIJ SZ INVENTOR F48 WHITNEY s. POWERS A TTOR/VEYS.

United States Patent Cffice 3,606,010 Patented Sept. 20, 1971 3,606,010 I GAS CLASSIFIER FOR CONTAINERS Whitney S. Powers, Pine City, N.Y., assignor to Powers Manufacturing, Inc., Elmira, N.Y. Filed Feb. 16, 1970, Ser. No. 11,496 Int. Cl. B07c /34 U.S. Cl. 20972 8 Claims ABSTRACT OF THE DISCLOSURE Defective bottles produced by a defective mold in a multi-element molding machine are first identified by an inspector by injecting a charge of fluid such as carbon dioxide gas. During later testing in transit, the presence of the fluid in a bottle is sampled to trigger a device for ejecting the bottle from the test line.

This invention relates to a gas classifier for containers. More particularly, this invention relates to apparatus for identifying defective bottles for subsequent removal from the production line.

Glass bottles produced by conventional multi-element molding machines, after passing through a cooling lehr, are randomly guided into a single line for various tests in transit. Before this jumbling takes place, it is customary for a Lehr Inspector to spot check the bottlm as they emerge from the lehr and to note any apparent defects. If he finds that one of the several molds is producing defective bottles, the bottles from that mold must be identified in some way so that they will be ejected from the test line. In practicing the present invention this is accomplished by locating a valved jet of carbon dioxide gas over each of the lines of bottles emerging from the lehr. The jets are positioned so that when the inspector opens the valve over the line of bottles produced by the defective mold, they receive a charge of said gas.

The identifying jet may remain open during the operation of the molding machine as long as the condition of the defective mold is not corrected, or if desired, the valve may be triggered to open when the bottle comes into registry therewith by any suitable means.

The bottles so identified are later ejected from the test line by using a tubular plug gauge and aspirating system for drawing out samples of the gas atmosphere contained by the bottles, while they are travelling in the test line. The atmosphere is directed into a small chamber containing a thermoelectric device having a high negative temperature coefficient of electrical resistance, known commercially as a thermistor. Since carbon dioxide gas has a lower thermal conductivity than air, the cooling effect of the atmosphere surrounding the thermistor is reduced. Therefore, the temperature of the thermistor rises, due to the current passing therethrough, and its electrical resistance is thereby lowered. An electrical system is provided which responds to this increased conductivity of the thermistor to trigger a means for ejecting the defective bottles from the line.

A necessary condition for employing the portion of the invention which effects injecting carbon dioxide gas into the bottles requires that the glass containers be aligned in rows parallel to the direction of lehr belt travel, each row having been produced by a given mold cavity from a multi-element molding machine.

It is an object of the invention to provide means for identifying bottles produced from a particular mold and separating them from the rest of the simultaneously molded bottles, without any contamination or physical change of any of the bottles.

The herein disclosed embodiment of the present invention incorporates conveying, testing and ejecting means disclosed in applicants prior Pat. No. 3,387,704 issued June 11, 1968, and application Ser. No. 638,254 filed May 15, 1967, now US. Pat. No. 3,496,761.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is a front elevation of a plug gauger as disclosed in applicants above cited patent, with the structure of the present invention installed thereon;

FIG. 2 is a rear elevation thereof, partly in section;

FIG. 3 is a block diagram of the pneumatic system; and

FIGS. 4a and 4b are schematic wiring diagrams of the electrical system.

Referring now to the drawings in detail, wherein like numerals indicate like elements, there is shown in FIG. 1 of the drawing a screw-conveyor 1 for bringing bottles 100, on a conveyor line to be tested, into vertical registry with a plug gauge 2 mounted on a reciprocating plunger 3 carried by a horizontally reciprocating carriage 4, all of which moving parts are so actuated from a motor 5 that the gauge 2 is inserted into the bottle and withdrawn therefrom while both are travelling through the test area in unison to the right as illustrated in FIG. 1. The structure whereby this is accomplished is shown and described in the Powers patent above cited and per se forms no part of the present invention so that further description is deemed unnecessary.

In the present structure the plug gauge 2 is caused to function as a sensing probe to sample the atmosphere within the bottle being gauged. For this purpose, the plug 2 and plunger 3 are traversed by a tubular conduit which is connected by a flexible hose 6 to the aspirating system shown in FIG. 3.

As shown in FIG. 3, atmospheric gas drawn through the plug gauge is caused to flow through a filter 7. From filter 7, which may be a centrifugal filter, part of the gas is drawn through a chamber 8 containing a thermistor. From there it passes through a low-volume flow meter 9 (0-10 cubic feet/hour, for example), a higher volume flow meter 11 (0-40 cubic feet/ hour, for example), and a second filter 12 to a motor-driven vacuum pump -13 which exhausts to the atmosphere through a mufller 14. A conduit 15 forms a by-pass around the thermistor chambet 8 permitting rapid passage of the air sample from the gauge probe 2 through the pneumatic system without making the entire atmosphere sample flow pass the thermistor. This arrangement accelerates the passage of the air sample through the pneumatic system and the purging of the system prior to reception of the subsequent sample, without subjecting the thermistor to the effects of high volume air flow. The proportion of the total air flow which is conducted through the thermistor chamber 8 is adjusted by means of a manually adjustable flow valve on the meter 9.

As shown in FIG. 4 of the drawing the thermistor 16, in series with a resistor 17 is bridged across a DC. voltage supply 18. The midpoint of the bridge is connected through a resistor 19 and blocking capacitor 20 to one input terminal 21 of an operational amplifier indicated conventionally at 22.

The second input terminal 23 is connected to ground, and the amplifier thus responds to the differences in voltage between input terminals 21 and 23 caused by changes in conductivity of the thermistor 16.

The output terminal 24 of the amplifier 22 is connected to one input terminal 25 of a second operational amplifier 26. The output terminal 24 is also connected to a feedback network 70 for balancing the voltage at terminal 21. A milli-ammeter 72 is connected between terminal 3 24 and ground. A current limiting resistor 74 is provided in series as shown. The second input terminal 27 of amplifier 26 is connected to the brush 28 of a potentiometer 29 which is bridged across the power supply 18. Potentiometer 29 provides a means whereby the static voltage of input terminal 27 may be adjusted.

The output terminal 31 of amplifier 26 is connected through a resistor 32 to a silicon controlled rectifier (SCR) 33 or any other rectifier of the type which, while normally non-conductive, will, when rendered conductive by eX- citation, remain conductive until the current flow therethrough is reduced to cut off; whereupon it again becomes non-conductive.

The SCR 33 is connected in series with the actuating coil 34 of a normally open relay 35, to the power supply 18, whereby said rectifier acts as a latch for the relay, maintaining the energization of the relay as long as the rectifier is conductive. A normally-closed single pole double throw micro-switch 36 (FIG. 2) is inserted in the lead from the positive terminal of the power supply 18 to the relay coil 34 to break and ground the latching circuit when opened.

Relay 35 is arranged to actuate a rejection system similar to that described and illustrated in applicants prior application Ser. No. 638,254, now US. Pat. No. 3,496,761 above cited. For this purpose, the terminal 37 of said relay is connected through a memory release solenoid 38 to one conductor 39 of an 110 AC. power line. Terminal 40 of relay 35 is connected through a normally-open interrogate micro-switch 42 to the other conductor 41 of the AC. power line.

As shown in FIG. 2, the micro-switches 36 and 42 are cam-operated by the clockwise rotating shaft 43; the interrogate switch 42 being so located as to be closed momentarily after latching relay 35 has had sufficient time to be caused to latch if a defective container has been sensed. The breaker switch 36 is so located as to be opened momentarily immediately subsequent to the closure of the interrogate switch 42, resetting the latching relay 35 and causing an interruption of current flow through SCR 33.

A visual alarm for signaling the presence of defective bottles is also provided. Rectifier 50 is connected to the secondary of transformer 52, and thus provides direct current to one terminal of neon lamp 54 through series voltage dropping resistor 56. The other terminal of neon lamp 54 is connected to the collector of transistor 58. The emitter of transistor 58 is connected to ground as shown. The base is connected through resistor 60 to terminal 31. The value of resistor 60 is chosen so that the transistor is biased into a conducting condition by the same voltage pulse that gates on SCR 33. The neon lamp thereafter conducts to provide the aforesaid visual alarm.

In operation, when a bottle is conveyed into the test area and into vertical registry with the plug gauge 2 (FIG. 1), said gauge is inserted into the bottle as it and the bottle are being traversed in unison, and air from the interior of the bottle is drawn therefrom through the pneumatic system including the thermistor chamber 8. Since there is a constant air flow through the pneumatic system as registered by the flow meters 9 and 11, the temperature of the thermistor normally remains substantially constant at a point somewhat above ambient temperature, due to the heating effect of the current traversing it from the power supply 18. If, however, a bottle containing carbon dioxide enters the test area, and the atmospheric sample drawn therefrom is so contaminated, the lower thermal conductivity of the gaseous mixture allows the thermistor temperature to rise. This reduces the voltage at the midpoint of the bridge circuit. This change in potential is conducted through the condenser 20 to the input terminal 21 of amplifier 22, and the consequent amplified signal from the output terminal 24 is conducted to the input terminal 25 of the second amplifier 26. The fixed voltage of the input terminal 27 of amplifier 26 is preset by manual adjustment of potentiometer 29 to provide a suitable threshold voltage for actuation of the rejection mechanism. If the signal received 'by input terminal 25 raises it voltage above the threshold voltage at input terminal 27, the differential voltage causes amplifier 26 to emit a voltage pulse from the output terminal 31 which gates on the SCR 33, thus energizing relay coil 34 to close contacts 37 and 40.

At a preselected point in the cycle of operation of the plug gauge, the interrogate micro-switch 42 is momentarily closed by the cam on the operating shaft 43. If, at this time, the relay contacts 37 and 40 are closed, current flows through the circuit including the memory release solenoid coil 38 thus causing closure of the rejector switch 44 and actuation of the rejection paddle 45 (FIG. 1) after a predetermined time delay to allow the defective bottle to reach the reject station, as shown and described in applicants prior application above cited.

Shortly after the closure of the interrogate switch, the cam on the operating shaft 43 momentarily opens the micro-switch 36 to break the arming circuit and thus prepare the system for the next test cycle.

Since thermistors are commercially available which can be arranged to have operational time cycles of very small fractions of a second, it will be understood that the identification and rejection process as above described is readily carried out at the normal speed of operation, of the testing devices (e.g., three per second) as disclosed in applicants prior patent and application.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the attributes thereof and, accordingly, reference should be made to the appended claims, rather that to the foregoing specification as indicating the scope of the invention.

What is claimed is:

1. Apparatus for identifying and separating individual containers from a jumbled succession of similar containers comprising means for introducing into chocen containers a charge of fluid having a physical characteristic identifiably different from air, sampling means for drawing out a sample of the atmosphere from each of the succession of containers as they pass through a test area, detection means for detecting the presence of said fluid in a sample so obtained, and means responsive to said detection means for initiating ejection of a container so distinguished.

2. A device as set forth in claim 1 in which said fluid has a coefficient of thermal conductivity which is different from air, said detection means including a thermoelectric device responsive to changes in the thermal conductivity of the surrounding atmosphere, and conduit means for conducting said samples of atmosphere in the container past said thermoelectric device.

3. A device as set forth in claim 2 in which the means for initiating ejection of the containers having injected fluid includes switch means, means whereby changes in the electrical conductivity of the thermoelectric device produces an electric signal which causes actuation of said switch means, and means actuated by said switch means for initiating ejection of the fluid charged container after a predetermined time delay.

4. A device as set forth in claim 3 in which the means for actuating the switch means comprises a latching circuit including a normally non-conductive electronic valve which is rendered conductive by a signal originated by said thermoelectric device.

5. A device as set forth in claim 4 in which the means for initiating ejection of the fluid charged containers comprises a solenoid which is connected to a source of power through said switch means and through an interrogate switch, and means for momentarily actuating the interrogate switch after the thermoelectric device has sampled the atmosphere of the container being tested.

6. A device as set forth in claim 5 in which said latching circuit also includes a normally closed breaker switch, and means for opening the breaker switch subsequent to the closure of the interrogate switch in order to restore the non-conductive state of the electronic valve.

7. A method for identifying and separating individual containers from a jumbled succession of similar containers comprising the steps of first introducing into chosen containers 2. charge of gaseous fluid having a physical characteristic identifiably different from air, sampling the atmosphere within each container by drawing out a sample of the atmosphere as each of the succession of containers pass through the testing area, detecting the presence of the gaseous fluid in a sample so obtained, and initiating ejection of a container so distinguished in response thereto.

8. Apparatus for identifying and separating individual glass containers from a jumbled succession of similar containers comprising jet means for introducing into chosen containers a charge of gaseous fluid having a measurable physical characteristic that is identifiably different from air, vacuum means for drawing out a sample of the atmosphere from each of the succession of containers as they pass through the test area, detection means for detecting the presence of said fluid in a sample so obtained, said fluid having a coefficient of thermal conductivity which is different from air, said detection means including a thermoelectric device responsive to changes in the thermal conductivity of the surrounding atmosphere, and means responsive to said detection means for initiating ejection of a container so distinguished.

References Cited UNITED STATES PATENTS 3,132,508 5/1964 Williams 209-72X 3,356,212 12/1967 Landin 209111.5 3,474,660 10/ 1969 Dooley 73-27 3,478,574 11/1969 Model! 7327 ALLEN N. KNOWLES, Primary Examiner 

